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3
Troubleshooting
This chapter describes how to troubleshoot your stack of hubs. Note that if
you have a Management Module, you can troubleshoot your hubs using
software. See the Management Module manual for more information.
This chapter describes how to troubleshoot your hub using:
■
solutions to common problems
■
LEDs
■
diagnostic tests
Solutions to Common Problems
Most problems are caused by the following situations:
■
Incorrect Hub-to-Hub connections. In addition to Extender Cable
hub-to-hub connections, you used crossover cable, thin coax, or fiber
cable to make hub-to-hub connections. Remove Switching Hub-toSwitching Hub connections other than the Extender Cable.
■
Loopback. Verify the Extender cable is not looped back to the same
hub:
Incorrect
Correct
■
Incorrect cable lengths. Maximum cable lengths are in the
HP Switching Hubs Installation Guide.
■
Bad cable or cable is not snug. Look for loose connections. If snug,
try a different cable.
■
Nonstandard cables. Miswired cables may cause numerous network collisions, and can seriously impair network performance. Use
a new correctly wired cable or compare your cable to the cable in
appendix A, “Cables and Connectors” for pinouts and correct cable
wiring.
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